The present invention relates to new and useful improvements in regenerators for industrial furnaces and especially glass melting furnaces. It is among the objects hereof to provide a method of operating a regenerator of the conventional checker tile and brick construction having a substantial array of air preheat surfaces to obtain maximum increase in the sensible heat of the clean air stream passed through the regenerator structure.
A supplemental volume of preheated air is passed through the preheat surfaces in addition to the combustion air required for the furnace fuel combustion under operating conditions and divided therefrom for passage to an auxiliary heat-utilizing apparatus mounted exteriorly of the furnace. The air is preheated as a unitary stream of substantial volume during its passage through the hot heat-exchanging surfaces of the regenerator and prior to diversion of at least one secondary portion to the auxiliary heat-utilizing apparatus. The heat recovery structure of the regenerator requires no modification except for providing an outlet orifice for the stated secondary portion of preheated air, preferably in a regiobn adjacent to the furnace combustion zone. Thus, the auxiliary heat-utilizing apparatus can be supplied with clean preheated air having a temperature ranging from about 1000.degree. to 2000.degree. F., for example, which can be employed for power generation or other purposes without unduly penalizing furnace operating conditions.
Another object of the present invention is to provide a method of deriving a significant amount of waste heat from the clean air side of the hot checkerwork region of a regenerator furnace in regulatable quantities without appreciably changing furnace operating conditions or structure. A supplemental hot clean air stream is obtained from the heated surfaces of the regenerator which can be diverted to achieve maximum utilization of the heat storage.
A still further object of the invention is to provide a method of recovering furnace waste gas energy in a clean form for use in a wide variety of auxiliary heat-requiring devices.